D) 36x^2-81
both 36x^2 and -81 are perfect squares
difference means subtraction
Answer: concentration = 15.58%
Step-by-step explanation:
Given: mass of sugar = 24 g = 24 ml [ ∵ 1 g = 1 ml]
Volume of solution = Quantity of water + quantity of solute
= 130 +24 ml
= 154 ml
Concentration = 

Hence, the concentration =15.58%
Answer:121
Step-by-step explanation:
Answer:
50
Step-by-step explanation:
12x + 15 = 5x + 85 {Subtract 15 from both sides}
12x + 15 - 15 = 5x + 85 - 15
12x = 5x + 70 {Subtract 5x from both sides}
12x - 5x = 70
7x = 70 {Divide both sides by 7}
x = 70/7
x = 10
∠U = 5x = 5*10 = 50